Many double-acting hydraulic suspension cylinders have separate snubbers for hydraulically cushioning or snubbing end-of-stroke motion in both rod extension and rod retraction directions. Such suspension cylinders typically have radially extending free-flow ports communicating the head end and rod end chambers during extension and retraction of the cylinder. Snubbing of the end-of-stroke movement during extension is accomplished by blocking fluid flow through the free-flow ports with the rod wear ring seated in a groove in the end cap. One of the problems encountered therewith is that blocking the free-flow passages occurs suddenly with little or no modulation. This results in a fairly harsh snubbing action and generates high pressure spikes that damage the seals and other components of the cylinder. Moreover, the high pressure oil flow through the free-flow ports impinging on the rod wear ring causes significantly increased wear thereof. Finally, assembly of the suspension cylinder is made more difficult since each separate snubber requires a number of distinct components.
Accordingly, it would be desirable to provide a suspension cylinder with a bidirectional snubber which does not use the wear rings for the snubbing action, gradually restricts oil flow between actuating chambers for reducing high pressure spikes and for increasing the duration of the snubbing action, and reduces the number of components for easy assembly.